“...Somewhere in my conscience I wondered whether this was the right thing to do,” an ex-employee recalled.

As the Iraqi insurgency raged during the height of the U.S. invasion of Iraq, a team of British employees manufactured phony al-Qaida propaganda videos inside a highly-secured building at a U.S. military base that was emblazoned with “do not enter” and “classified” signs, the Bureau of Investigative Journalism revealed.

Bell Pottinger, a U.K. public relations firm known for softening the image of the hawkish Margaret Thatcher’s steely image, contracted with the U.S. Pentagon to produce the videos in Baghdad’s Camp Victory headquarters.

Martin Wells, a former employee, said he was given precise instructions: “We need to make this style of video and we’ve got to use al-Qaida’s footage,” he was told. “We need it to be 10 minutes long, and it needs to be in this file format, and we need to encode it in this manner.”

Wells could never have been prepared for what he was getting himself into, when the video editor interviewed with Bell Pottinger in 2006, in what turned out to be an experience that was "shocking, eye-opening, life-changing” for him.

Working as a freelancer, his agency suggested interviewing for the potential new gig.

“You’ll be doing new stuff that’ll be coming out of the Middle East,” he was told.

“I thought ‘That sounds interesting’,” Wells recalled to the Bureau. “So I go along and go into this building, get escorted up to the sixth floor in a lift, come out and there’s guards up there. I thought what on earth is going on here? And it turns out it was a Navy post, basically. So from what I could work out it was a media intelligence gathering unit.”

After his interview, when Wells asked when he would find out about the job, he was told, “You’ve already got it … We’ve already done our background checks into you.”

Within 48 hours he was flown to Baghdad, where he worked for the better part of two years inside the belly of the U.S. military intelligence operation.

“It was a very secure building," he said of his first impressions of his new workplace, “with signs outside saying ‘Do not come in, it’s a classified area, if you’re not cleared, you can’t come in.’”

“I made the mistake of walking into one of the (U.S. military) areas, and having a very stern American military guy basically drag me out saying you are not allowed in here under any circumstances, this is highly classified, get out—whilst his hand was on his gun, which was a nice introduction,” said Wells.

The London-based PR agency was brought into Iraq soon after the U.S. invasion, and the massive media operation employed almost 300 British and Iraqi staff at one point.

The firm’s work in Iraq was reported to all of the Pentagon, the CIA and the National Security Council. Former General David Petraeus – then commander of the coalition forces in Iraq - and occasionally even the White House signed off on the work produced.

The Bureau found transactions of up to US$540 million between Pentagon and Bell Pottinger for information and psychological operations on a number of contracts between May 2007 to December 2011.

Bell Pottinger's former chairman Lord Tim Bell told the Sunday Times, who collaborated in their investigation with the Bureau, that the bulk of the money was for costs such as production and distribution. The firm still earned around US $20 million a year in fees, however.

The firm’s operations on behalf of the U.S. government stopped in 2011 when American troops withdrew from Iraq, and the company changed ownership after a management buyout in 2012. Its current structure has no connections with the unit Wells worked for, and the unit denies any involvement with tracking software as described by Wells.

With the aim of Bell Pottinger’s work in Iraq to highlight al-Qaida’s senseless violence, Wells said at the time he thought he was doing some good work. “But then, somewhere in my conscience I wondered whether this was the right thing to do,” he added.